High density cabled midplanes and backplanes

ABSTRACT

A cabled midplane includes a first support plate along a plane between a first connector set and a second connector set that connect to line cards on either side of the cabled midplane. The first connector set and the second connector set include connector slices. A wiring sub-layer includes cable slices to provide a connection between the first connector slice of a connector of the first connector set to the first connector slice of a connector of the second connector set, such that the first wiring sub-layer connects each connector of the first connector set, through one cable slice, to a connector of the second connector set. Additional wiring sub-layers are added, and a second support plate, parallel to the first support plate, is provided to encase and support the wiring sub-layers between the first support plate and the second support plate. Other apparatuses and methods are described.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/578,707, filed Dec. 22, 2014, which is incorporated by referenceherein in its entirety.

TECHNICAL FIELD

Embodiments described generally herein relate to backplanes andmidplanes. Some embodiments relate to cabled backplanes and midplanes.

BACKGROUND

Many high speed network switches require high connector density on abackplane or a midplane. Printed circuit board (non-cabled) backplanesand midplanes may implement extensive interconnect lengths and canexperience high levels of signal loss. Cabled midplane and backplanetechnologies may require large amounts of space and mechanical supportto achieve the large number of connections required for high speednetworking applications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a midplane connector envelope forpurposes of describing example embodiments.

FIG. 2 is a perspective view of a Director Class Network Switch (DCNS)illustrating tight line card pitch for purposes of describing exampleembodiments.

FIG. 3 is a front view of the backplane connector envelope for purposesof describing example embodiments.

FIG. 4 illustrates an interconnect topology when all connectors on oneside of the midplane are connected to all connectors on the other sideof the midplane in accordance with some embodiments.

FIG. 5 is a flow chart showing a method for manufacturing a midplane inaccordance with some embodiments described herein.

FIG. 6 illustrates a wiring sub-layer in accordance with someembodiments described herein.

FIG. 7 illustrates a connector-wide wiring layer in accordance with someembodiments described herein.

FIG. 8 illustrates a complete first wiring layer and a first portion ofa second wiring layer in accordance with some embodiments describedherein.

FIG. 9 illustrates standoffs and support tabs in accordance with someembodiments described herein.

FIG. 10 illustrates standoffs between support plates of two wiringlayers in accordance with some embodiments described herein.

FIG. 11 illustrates inner and outer support plates for encasing twowiring layers in accordance with some embodiments described herein.

FIG. 12 illustrates a cabled midplane assembly with wiring layers and apower layer in accordance with some embodiments described herein.

FIG. 13A illustrates a wiring diagram showing a first layer ofindividual, full swizzle connections of a cabled midplane in accordancewith some embodiments described herein.

FIG. 13B illustrates a wiring diagram showing a second layer ofindividual, full swizzle connections of a cabled midplane in accordancewith some embodiments described herein.

FIG. 13C illustrates a wiring diagram showing a third layer ofindividual, full swizzle connections of a cabled midplane in accordancewith some embodiments described herein.

FIG. 13D illustrates a wiring diagram showing a fourth layer ofindividual, full swizzle connections of a cabled midplane in accordancewith some embodiments described herein.

FIG. 13E illustrates a wiring diagram showing a fifth layer ofindividual, full swizzle connections of a cabled midplane in accordancewith some embodiments described herein.

FIG. 14 illustrates a communication device in accordance with someembodiments described herein.

DETAILED DESCRIPTION

A medium-to-large network switch typically includes multiple switchchips, all interconnected to form a specific network topology. Such anetwork switch is often referred to as a Direct Class Network Switch(DCNS). High speed network switches today include ever-increasingnumbers of network ports. Additionally, these high speed networkswitches have been called upon to provide ever-increasing signalingrates. In order to deal with these two trends, system architectscontinue to package an increasingly large number of high speed portswithin a single DCNS chassis, leading to a significant increase inpackaging density and interconnect length. Printed circuit board (PCB)midplane and backplane technologies can no longer achieve the highconnector densities used to interconnect switch chips internal to aDCNS. Additionally, PCB midplanes and backplanes exhibit increasedsignal losses at higher signaling rates, and therefore can no longersupport increased interconnect lengths between network switch chipsinternal to the DCNS. Cabled backplane and midplane technologies cansupport significantly increased connector densities, and can minimizeinsertion loss of high speed channels and thus support longer channellengths used with larger DCNS chassis sizes. However, it is difficultand costly to manage the thousands of cables required to construct largecabled backplanes and midplanes.

Embodiments described herein provide methods for fabrication of highdensity cabled backplanes and midplanes. Methods in accordance with someembodiments provide for fabricating cabled backplanes and mid planes bysequentially adding wiring sub-layers and layers, power distributionlayers, and mechanical support layers. By using this layered approach,embodiments enable a very high connector density. Furthermore, someembodiments provide a cable swizzle (e.g., a “many to many”interconnect) methodology, on a layer basis, in a repeatable andtherefore manufacturable process.

Available cabled backplanes are constructed using bundles of conductors,added sequentially. This method works well when mechanical supportinfrastructure is substantial (which limits the effective connectordensity) and when the bundles are essentially point-to-point. However,manufacturing of such a backplane is costly and difficult when the spacefor mechanical infrastructure must be minimized to achieve higheffective connector density, or when a full swizzle (e.g., all-to-allinterconnect pattern) is needed.

FIGS. 1-4 are provided to illustrate some of the challenges addressedwith various embodiments. FIG. 1 is a perspective view of a line cardmodule showing the midplane/backplane connector envelope 100. Thebackplane connector envelope 100 has a card width 102 that maximizesconnector packaging density by reducing spacing between the connectors104 (of which four are shown per line card in FIG. 1) and the guidemodules 106 (of which two are shown per line card in FIG. 1). A minimumvertical pitch 108 between adjacent line cards 110, 112 leaves littlespace for mechanical support infrastructure. A power module 114 suppliespower to the line cards 110, 112.

FIG. 2 is a perspective view of a DCNS illustrating tight card pitch.Midplane connections (not shown in FIG. 2) will connect through amidplane interconnect 202. The number of line cards 204 in a very highport count DCNS 200 exhibits a tight card pitch, which allows littleroom for mechanical support.

FIG. 3 is a front view of the backplane connector envelope 100 shown inFIG. 1 showing additional line cards. FIG. 3 serves to furtherillustrate the minimal card width 102 and vertical pitch 108 thatpermits minimal space between line cards 110, 112 for mechanicalsupport.

FIG. 4 illustrates an interconnect topology when all connectors on oneside of the midplane 400 are connected to all connectors on the otherside of the midplane 400 in accordance with some embodiments. However,embodiments are not limited to the interconnect topology shown in FIG.4, but rather embodiments can include a variety of interconnecttopologies, including a complete all-to-all topology. It may bedifficult or costly to manufacture an all-to-all interconnected cabledbackplane or midplane 400 in a repeatable, reliable fashion because ofthe relatively high number of conductors 402 included in such abackplane or midplane 400 and/or the high level of conductor cross-overrequired to achieve an all-to-all type interconnect. In someembodiments, conductors can include copper wires, optical fibers,twisted shielded wires, coaxial cables, etc., although embodiments arenot limited to any particular type of conductor. In the one-to-oneconnection illustrated in FIG. 4, each line card 404, 406, 408, 410,412, and 414 on one side of the midplane 400 has a connection to everyline card 416, 418, 420, 422, 424, and 426 on the other side of themidplane 400.

Embodiments provide a repeatable, reliable method for manufacturing ahigh density (e.g., “all-to-all” or “many-to-many”) interconnectedmidplane or backplane such as those illustrated in the various views ofFIGS. 1-4.

FIG. 5 is a flow chart showing a method 500 for manufacturing a midplanein accordance with some embodiments described herein. Embodiments canalso relate to manufacturing a backplane. The midplane or backplane madeby method 500 may include a midplane or backplane such as could be usedwith the assemblies illustrated in FIGS. 1-4. The method 500 isdescribed with reference to some elements illustrated in FIGS. 6 and 7.

FIG. 6 illustrates a wiring sub-layer 600 in accordance with someembodiments described herein. Individual conductors (not shown in FIG.6) are terminated on both ends A and B with electrical contacts (notshown in FIG. 6) and assembled into cable slices 602. The individualconductors may couple through, for example, male/female coupling or anyother coupling, with the connector slice 604A. The cable slices 602 arepoint-to-point. The cable slices 602 are grouped into a wiring sub-layer600. The wiring sub-layer 600 includes a full set of cable slices 602 toconnect to each line card 404, 406, 408, 410, 412, 414, 416, 418, 420,422, 424 and 426 (FIG. 4) locations. Cable slices 602 cross over eachother in such a way that there is at most a single crossover between anytwo conductors within the cable slices 602. Furthermore, there is atmost a single crossover between any two conductors at any point. Thisreduces or minimizes bulk conductor buildup to achieve higherwiring/connector density. Furthermore, 402 (FIG. 4) is comprised of aplurality of sub-layers 600.

The illustrated wiring sub-layer 600 is mounted on a support plate 606.The support plate 606 can include one or more guide pins 608 for linecard guidance and alignment during line card insertion. The guide pins608 can displace the support plate 606 from the wiring sub-layer 600 bya distance along an axis (e.g., the x-axis). The support plate 606 canalso include a series of holes (not shown in FIG. 6) in which supportrods 610 can be added. Support rods 610 are described in more detailbelow with reference to FIG. 8.

FIG. 7 illustrates a connector-wide wiring layer 700 in accordance withsome embodiments described herein. FIG. 7 further serves to illustratemultiple connector slices 604A-604J of connector sets 702, 704 that arecollected in connector shrouds 701. Additional wiring sub-layers (notshown in FIG. 7) similar to the wiring sub-layer 600 shown in FIG. 6,can be added sequentially in accordance with various embodiments until awiring layer with a width equal to a connector width is constructed.Connector set 702, 704 width (e.g., shroud width or organizer width),and therefore the number of connector slices 604 in a wiring layer 700,will vary based on manufacturer preferences. In some embodiments,connector shrouds 701 include 4, 6, or 8 connector slices 604, andtherefore up to 4, 6, or 8 wiring sub-layers 600, respectively, could beadded to create a wiring layer 700 with a width of 4, 6, or 8. However,in some embodiments the number of connector slices 604 can be 16 or 20slices, or more.

Referring to FIG. 5, the method 500 begins at operation 502 withproviding a support plate 606 along a plane (e.g., the y-plane) betweentwo connector sets 702 and 704. One connector set 702 includes aplurality of connectors 708, 720, 722, 724, 726, 728 to connect torespective line cards on a first side B of the cabled midplane. Theother connector set 704 includes a plurality of connectors 706, 710,712, 714, 716, 718 to connect to respective line cards on a second sideA of the cabled midplane.

Connectors of the two connector sets 702 and 704 include connectorslices 604A-604J. The connector slices in each connector set 702 and 704include at least a first connector slice 604A that is a nearest distancealong an axis (e.g., the x-axis) from the support plate 606 and a secondconnector slice 604J that is further than the first connector slice 604Aalong the axis from the support plate 606.

In FIG. 5, the method 500 continues at operation 504 with providingwiring sub-layers 600. Operation 504 includes providing a first wiringsub-layer 600 by mounting a first plurality of cable slices 602 on thesupport plate 606. Cable slices 602 can be mounted such that individualconductors within each cable slice 602 crosses over other conductors atno more than one point in the plane between the connector sets 702 and704. Further, cable slices 602 can be mounted such that any point in theplane between connector sets 702, 704 includes no more than one instanceof a conductor crossover.

Each cable slice 602 in this wiring sub-layer 600 provides a connectionbetween the first connector slice (e.g., the connector slice 604Aclosest to the support plate 606) of a connector 706 of one connectorset 704 to the first connector slice of a connector 708 of the secondconnector set 702, such that the first wiring sub-layer connects eachconnector 706, 710, 712, 714, 716 and 718 of one connector set 704,through one cable slice 602, to a connector 708, 720, 722, 724, 726, and728 of the other connector set 702. For example, referring to FIG. 7,connector 706 can be connected by a cable slice 602 of the firstsublayer to connector 724 of the second connector set 702. At the sametime, using different cable slices 602, connector 710 can be connectedto connector 726, connector 712 can be connected to connector 728,connector 714 can be connected to connector 708, connector 716 can beconnected to connector 720, and connector 718 can be connected toconnector 722.

In FIG. 5, operation 504 further includes providing at least a secondwiring sub-layer 600 by connecting a second plurality of cable slices602. Each cable slice 602 in the second wiring sub-layer 600 provides aconnection between a second connector slice (e.g., a connector slicespaced a further distance than the first connector slice from thesupport plate 606) of a connector of one connector set 704 to a secondconnector slice of a connector of the other connector set 702. As withthe first wiring sub-layer 600, the second wiring sub-layer 600 connectseach connector of one connector set 704, through one cable slice 602, toa connector of the other connector set 702. The cable slices 602 of thesecond wiring sub-layer 600 can be connected such that a connector ofone connector set 704 is connected to a different connector of the otherconnector set 702 in the second wiring sub-layer 600 than it wasconnected to in the first wiring sub-layer 600. For example, asconnector 706 was connected to connector 728 in the first wiringsub-layer 600, connector 706 may not be connected to connector 728 inthe second wiring sub-layer 600.

In accordance with embodiments, wiring sub-layers 600 are addedsequentially until a connector-wide layer is constructed. The method 500can further include testing electrical connectivity within a wiringsub-layer 600 prior to providing subsequent wiring sub-layers 600.Additionally, the method 500 can include testing each individual cableslice 602. Wiring sub-layers 600 can be added to the width of connectorsets 702 and 704 to connect some or all of connector slices 604A-J.

Connector sets 702 and 704 can each be encased in a connector shroud ororganizer. Connector width (e.g., shroud width) and therefore the numberof slices 604 the connector set 702, 704 contains, depends on connectorset 702, 704 manufacturer preferences. Typically, shrouds are made tocontain 4, 6 or 8 slices, but can be as large as 16 or 20 slices, ormore.

In FIG. 5, the example method 500 continues at operation 506 withproviding an additional support plate, parallel along the first plane(e.g., the y-axis) to the support plate 606, to encase wiring sub-layers600 between the additional support plate and the first support plate andto form a wiring layer at least somewhat similar to the structure shownin FIG. 8.

FIG. 8 illustrates a first wiring layer and a wiring sub-layer 800 withcable slices 802 of a second wiring layer in accordance with someembodiments described herein. Support plates 606 and 804 are orientedparallel to wiring sub-layers (not shown in FIG. 8). Support plates 606and 804 act as mechanical support layers. By placing support plates 606and 804 in the manner shown in FIG. 8, manufacturers can minimize thespace used for mechanical support.

In some embodiments, support plates 606 and 804 have a series ofopenings in which to insert support elements, for example, support rods610. These support rods 610 slide between connector slices 604A-604J ofadjacent midplane connectors (not shown in FIG. 8). The support rods 610can align connector slices 604A-604J and provide support for connectorsets 702, 704 during line card insertion and de-insertion. The supportrods 610, or another support element, can prevent movement of the twoadjacent connectors in a direction, e.g., along the y-axis and z-axis,while the support plates 606 and 804 prevent movement of connectors in adifferent direction, e.g., along the x-axis.

The support rods 610 are extended to align wiring sub-layers and toalign and join wiring layers as they are added. In some embodiments,support rods 610 are extended to engage the support plate 804 asadditional wiring layers are added.

In some embodiments, the holes in the support plates 606 and 804 engagesupport tabs (not shown in FIG. 8, reference 905 in FIGS. 9 and 10)protruding from the walls of connector shrouds, instead of support rods.Support tabs can be used by providing a slot or a groove within thesupport plates 606 and 804. For example, the grooves in the supportplates 606 and 804 can capture the support tabs on the connectors anddisallow the connectors to move along the y-axis and z-axis.

In accordance with embodiments, cable slices 602 are snapped intoconnector shrouds on a wiring sub-layer 600 basis, and connector shroudsare supported by support plates at least somewhat similar to supportplates 606 and 804. Different mechanisms can be used to fasten supportplates 606 and 804 to each other or to other support plates. In someembodiments standoff mechanisms are used.

For example FIG. 9 illustrates standoffs 903 and support tabs 905 inaccordance with some embodiments described herein. FIG. 10 illustratesstandoffs 903 between support plates 606, 804, and 1104 of two wiringlayers in accordance with some embodiments described herein. FIG. 10further illustrates support tabs 905 that have been added by providing aslot or a groove within the support plate 1004. There can also be slotsor grooves within the other support plate 804 and within any othersupport plates in accordance with various embodiments. The grooves (notshown in FIG. 9 or 10) in the support plates 606, 804, 1004, etc., cancapture support tabs 905 on the connectors of the connector sets 702,704 to provide alignment and disallow the connectors to move along they-axis and z-axis. Additionally, standoffs 903 are provided to fastensupport plates 606 and 804 to each other, and to fasten support plates804 and 1004 to each other.

The method 500 can include adding several wiring layers through aprocess of adding support plates between wiring layers. FIG. 11illustrates an inner support plate 804 and outer support plates 606 and1004 for encasing two wiring layers in accordance with some embodiments.The method 500 can further include providing a power layer between atleast any two wiring layers.

FIG. 12 illustrates a cabled midplane assembly 1200 with wiring layersand a power layer 1202 in accordance with some embodiments describedherein. In the example of FIG. 12, the cabled midplane assembly 1200includes four wiring layers (not shown in FIG. 12) between outer supportplates 606 and inner support plates 804, and a power layer 1202 inaccordance with some embodiments described herein. The power layer 1202including power connections 1204 for providing power to line cards (notshown in FIG. 12) on the first side A of the cabled midplane assembly1200 and to line cards on the second side B of the cabled midplaneassembly 1200. In some embodiments, the power layer 1202 is notconnected to wiring sub-layers. In some embodiments, the power layer1202 includes or is coupled to distribution elements using, for example,discrete wiring or planar bus bar distribution, to bring power from apower supply bay (not shown) to the line cards 404, 406, 408, 410, 412,414, 416, 418, 420, 422, 424 426 (FIG. 4).

FIG. 12 further depicts fully-engaged support rods 610. All supportplates 606 and 804 are oriented parallel to each other and consumeminimal space, which enables highest connector density. The supportplates 606 and 804 enclose the wiring layers and support connectors1206, 1208, 1210, 1212, 1214, 1216, 1218 and 1220 during line cardinsertion and removal.

Some or all of operations 502, 504 and 506 may be performed concurrently(e.g., simultaneously). Method 500 may include other operations besidesoperations 502, 504 and 506, such as attaching a device (e.g., cabledmidplane assembly 1200) on a circuit board, forming connections, andother activities, so that the a midplane or backplane made by method 500may include components similar to or identical to those described abovewith reference to FIG. 1 through FIG. 4.

An assembly methodology proposed herein addresses a need for a reliable,repeatable, cost effective way to manufacture a very large conductorcount, all-to-all interconnected cabled backplanes and mid-planes. Italso enables to achieve a very high density backplane styleinterconnect.

FIGS. 13A, 13B, 13C, 13D, and 13E illustrate layers of a full swizzlewiring diagram in accordance with some embodiments described herein. Forexample, the layers in each of FIGS. 13A, 13B, 13C, 13D, and 13E, takentogether, illustrate a full wiring diagram of fabric ports through amidplane such as the midplanes described with reference to FIGS. 1-12.The illustrative example of FIGS. 13A, 13B, 13C, 13D, and 13E depict a2-tier tree fabric topology, with tier 1 switch cards on one side A ofthe midplane and tier 2 switch cards on the other side B. For thistopology, each sub-layer connects each connector on the tier 1 switchside A to one connector on the tier 2 switch side B. Each layer 1302,1304, 1306, 1308 and 1310 has a different wiring diagram, complementaryto the other wiring diagrams. Altogether, the full set of layers 1302,1304, 1306, 1308 and 1310 form a full swizzle wiring, thus collectivelyachieve all (tier 1)-to-all (tier 2) fabric interconnect.

In addition to high speed fabric interconnect and power distributionlayers, other layers can be added in various embodiments to address theneed for low speed interconnect for management signals, among otherpossible uses and needs. The wiring and assembly methodology describedabove with respect to various embodiments is applicable to trees andother fabric topologies, as well as to backplane and midplanestructures.

FIG. 14 illustrates a communication device 1400 in accordance with someembodiments described herein. The communication device 1400 can includea cabled midplane 1402. In some embodiments, the communication device1400 can include a backplane. As described earlier herein with referenceto FIGS. 6-7, the cabled midplane 1404 includes connector sets 1404 and1406, on either side of the cabled midplane 1402. Each connector set1404 and 1406 includes connectors to connect to respective line cards1408 and 1410 on either side of the cabled midplane 1402. Thecommunication device 1400 can serve as a switching system with at leastone communication port 1412, or as any other device in a data centerfabric, although embodiments are not limited thereto.

The illustrations of the apparatuses (e.g., wiring sub-layers 600, cableslices 602, communication devices 1400) and methods (e.g., method 500)described above are intended to provide a general understanding of thestructure of different embodiments and are not intended to provide acomplete description of all the elements and features of an apparatusthat might make use of the structures described herein.

The apparatuses, devices, and methods described above may include or beincluded in high-speed computers, communication and signal processingcircuitry, single or multi-processor modules, single or multipleembedded processors, multi-core processors, message informationswitches, and application-specific modules including multilayer,multi-chip modules. Such apparatuses may further be included assub-components within a variety of other apparatuses (e.g., electronicsystems), such as televisions, cellular telephones, personal computers(e.g., laptop computers, desktop computers, handheld computers, etc.),tablets (e.g., tablet computers), workstations, radios, video players,audio players (e.g., MP3 (Motion Picture Experts Group, Audio Layer 3)players), vehicles, medical devices (e.g., heart monitor, blood pressuremonitor, etc.), set top boxes, and others.

ADDITIONAL NOTES AND EXAMPLES

Example 1 includes subject matter including a method of making anelectronic apparatus (e.g., a cabled midplane, a cabled backplane,etc.), the method comprising providing a first support plate along aplane between a first connector set and a second connector set, thefirst connector set including a plurality of connectors to connect torespective line cards on a first side of the cabled midplane, the secondconnector set including a plurality of connectors to connect torespective line cards on a second side of the cabled midplane,connectors of the first connector set and the second connector setincluding a plurality of connector slices, the plurality of connectorslices including at least a first connector slice that is a firstdistance along a first axis from the first support plate and a secondconnector slice that is a second distance, further than the firstdistance, along the first axis from the first support plate; andproviding a first wiring sub-layer by mounting a first plurality ofcable slices on the first support plate, each cable slice of the firstplurality of cable slices to provide a connection between the firstconnector slice of a connector of the first connector set to the firstconnector slice of a connector of the second connector set, such thatthe first wiring sub-layer connects each connector of the firstconnector set, through one cable slice, to a connector of the secondconnector set.

In Example 2, the subject matter of Example 1 may optionally includeproviding at least a second wiring sub-layer by connecting a secondplurality of cable slices, each cable slice of the second plurality ofcable slices to provide a connection between the second connector sliceof a connector of the first connector set to the second connector sliceof a connector of the second connector set, such that the second wiringsub-layer connects each connector of the first connector set, throughone cable slice, to a connector of the second connector set; andproviding a second support plate, parallel to the first support plateand parallel to the first wiring sub-layer and the second wiringsub-layer, to encase the first wiring sub-layer and the second wiringsub-layer between the second support plate and the first support plateand to form a first wiring layer.

In Example 3, the subject matter of Example 2 may optionally includewherein providing the second wiring sub-layer includes connecting thesecond plurality of cable slices such that a connector of the firstconnector set is connected to a different connector of the secondconnector set in the second wiring sub-layer than the respectiveconnector of the first connector set is connected to in the first wiringsub-layer.

In Example 4, the subject matter of any of Examples 1-3 may optionallyinclude providing a plurality of wiring sub-layers such that eachconnection in each connector in the first connector set is connected,through a separate connector slice, to each connection in each connectorin the second connector set.

In Example 5, the subject matter of any of Examples 1-4 may optionallyinclude testing electrical connectivity within the first wiringsub-layer, prior to providing the second wiring sub-layer.

In Example 6, the subject matter of any of Examples 1-2 may optionallyinclude providing at least one opening in the first support platebetween any two adjacent connectors of each of the first connector setand the second connector set; and preventing movement of the twoadjacent connectors in a direction along a second axis different fromthe first axis by inserting a support element in the at least oneopening.

In Example 7, the subject matter of Example 6 may optionally includewherein the support element includes a tab 1003 (FIG. 10) on at leastone connector and a groove on at least the first support plate withinwhich the tab is captured to prevent movement of the at least oneconnector.

In Example 8, the subject matter of Example 6 may optionally includewherein the support element includes a support rod.

In Example 9, the subject matter of Example 8 may optionally includeproviding a second wiring layer including at least a first wiringsub-layer mounted to a second side of the second support plate separatedfrom the second wiring sub-layer of the first wiring layer, and furtherproviding a third support plate to encase the first wiring sub-layer ofthe second wiring layer between the second support plate and the thirdsupport plate; and extending the support rod by a connector width of athird connector mounted to the second support plate, to join the firstwiring layer and the second wiring layer.

In Example 10, the subject matter of Example 9 may optionally includeproviding a power layer between the second wiring layer and the firstwiring layer, the power layer including power connections for providingpower to line cards on the first side of the cabled midplane and to linecards on the second side of the cabled midplane.

In Example 11, the subject matter of any of Examples 1-10 may optionallyinclude wherein mounting the first plurality of cable slices includesmounting a plurality of conductors such that a conductor crosses overother conductors of the plurality of conductors at no more than onepoint in the plane between the first connector set and the secondconnector set.

In Example 12, the subject matter of any of Examples 1-11 may optionallyinclude wherein mounting the first plurality of cable slices furtherincludes connecting the plurality of conductors such that any point onthe plane between the first connector set and the second connector setincludes no more than one instance of a conductor crossover betweenconductors of the plurality of conductors.

In Example 13, the subject matter of any of Examples 1-12 may optionallyinclude wherein providing the first support plate includes providingguide pins to displace the first support plate from the first wiringsub-layer by a distance along the first axis.

Example 14 includes subject matter (such as a cabled midplane, a cabledbackplane, etc., or electronic system apparatus, or machine) including afirst support plate along a plane between a first connector set and asecond connector set, the first connector set including a plurality ofconnectors to connect to respective line cards on a first side of thecabled midplane, the second connector set including a plurality ofconnectors to connect to respective line cards on a second side of thecabled midplane, connectors of the first connector set and the secondconnector set including a plurality of connector slices, the pluralityof connector slices including at least a first connector slice that is afirst distance along a first axis from the first support plate and asecond connector slice that is a second distance, further than the firstdistance, along the first axis from the first support plate; and a firstwiring sub-layer including a first plurality of cable slices mounted onthe first support plate, each cable slice of the first plurality ofcable slices to provide a connection between the first connector sliceof a connector of the first connector set to the first connector sliceof a connector of the second connector set, such that the first wiringsub-layer connects each connector of the first connector set, throughone cable slice, to a connector of the second connector set.

In Example 15, the subject matter of Example 14 may optionally includeat least a second wiring sub-layer including a second plurality of cableslices, each cable slice of the second plurality of cable slices toprovide a connection between the second connector slice of a connectorof the first connector set to the second connector slice of a connectorof the second connector set, such that the second wiring sub-layerconnects each connector of the first connector set, through one cableslice, to a connector of the second connector set; and a second supportplate, parallel to the first support plate, to encase the first wiringsub-layer and the second wiring sub-layer between the second supportplate and the first support plate and to form a first wiring layer ofthe cabled midplane.

In Example 16, the subject matter of any of Examples 14-15 canoptionally include a power layer.

In Example 17, the subject matter of Example 16 can optionally include,wherein the power layer is not connected to conductors of either thefirst wiring sub-layer or the second wiring sub-layer.

In Example 18, the subject matter of Example 15 can optionally includewherein a connector of the first connector set is connected to adifferent connector of the second connector set in the second wiringsub-layer than the respective connector of the first connector set isconnected to in the first wiring sub-layer.

In Example 19, the subject matter of any of Examples 14-18 canoptionally include wherein each cable slice includes a plurality ofconductors, and wherein, cable slices are mounted such that a conductorcrosses over other conductors of the plurality of conductors at no morethan one point in the plane between the first connector set and thesecond connector set.

Example 20 includes subject matter (such as a device, a communicationdevice, electronic system, or machine) including a cabled midplane (orbackplane, etc.) including a first connector set and a second connectorset, the first connector set including a plurality of connectors toconnect to respective line cards on a first side of the cabled midplane,the second connector set including a plurality of connectors to connectto respective line cards on a second side of the cabled midplane,connectors of the first connector set and the second connector setincluding a plurality of connector slices; a first support platepositioned along a plane between the first connector set and the secondconnector set, wherein the plurality of connector slices include atleast a first connector slice that is a first distance along a firstaxis from the first support plate and a second connector slice that is asecond distance, further than the first distance, along the first axisfrom the first support plate; and a first wiring sub-layer including afirst plurality of cable slices mounted on the first support plate, eachcable slice of the first plurality of cable slices to provide aconnection between the first connector slice of a connector of the firstconnector set to the first connector slice of a connector of the secondconnector set, such that the first wiring sub-layer connects eachconnector of the first connector set, through one cable slice, to aconnector of the second connector set; a first line card coupled to aconnector on the first side of the cabled midplane; and a second linecard coupled to a connector on the second side of the cabled midplane.

In Example 21, the subject matter of Example 20 may optionally include,wherein the communication device includes a switching system with atleast one communication port.

The above description and the drawings illustrate some embodiments toenable those skilled in the art to practice embodiments. Otherembodiments may incorporate structural, logical, electrical, process,and other changes. Examples merely typify possible variations. Portionsand features of some embodiments may be included in, or substituted for,those of other embodiments. Many other embodiments will be apparent tothose of skill in the art upon reading and understanding the abovedescription. Therefore, the scope of various embodiments is determinedby the appended claims, along with the full range of equivalents towhich such claims are entitled.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b)requiring an abstract that will allow the reader to ascertain the natureand gist of the technical disclosure. It is submitted with theunderstanding that it will not be used to limit or interpret the scopeor meaning of the claims. The following claims are hereby incorporatedinto the detailed description, with each claim standing on its own as aseparate embodiment.

What is claimed is:
 1. A cabled midplane comprising: a first connectorset and a second connector set, the first connector set including aplurality of individual connectors to connect to respective line cardson a first side of the cabled midplane, the second connector setincluding a plurality of individual connectors to connect to respectiveline cards on a second side of the cabled midplane, wherein eachindividual connector of the first connector set and the second connectorset includes a plurality of connector slices including a correspondingfirst-position connector slice and a corresponding second-positionconnector slice, and wherein each connector slice of the plurality ofconnector slices of each individual connector includes acollinearly-situated set of contacts; a first wiring sub-layer includinga first plurality of cable slices, each cable slice of the firstplurality of cable slices to provide a set of conductors between afirst-position connector slice of a corresponding individual connectorof the first connector set to a first-position connector slice of acorresponding individual connector of the second connector set, suchthat the first wiring sub-layer connects each first-position connectorslice of the first connector set, through one corresponding cable slice,to a first-position connector slice of the second connector set, andwherein each cable slice of the first plurality of cable slices isarranged generally coplanarly; and a second wiring sub-layer including asecond plurality of cable slices, each cable slice of the secondplurality of cable slices to provide a set of conductors between asecond-position connector slice of a corresponding individual connectorof the first connector set to a second-position connector slice of acorresponding individual connector of the second connector set, suchthat the second wiring sub-layer connects each second-position connectorslice of the first connector set, through one corresponding cable slice,to a second-position connector slice of the second connector set, andwherein each cable slice of the second plurality of cable slices isarranged generally coplanarly.
 2. The cabled midplane of claim 1,further comprising: a first support plate along a plane between thefirst connector set and the second connector set.
 3. The cabled midplaneof claim 1, wherein the first connector set is encased in a firstconnector shroud and the second connector set is encased in a secondconnector shroud.
 4. The cabled midplane of claim 3, further comprisingfirst support tabs protruding from walls of the first connector shroudand second support tabs protruding from walls of the second connectorshroud to mount to grooves within a second support plate parallel to thefirst support plate.
 5. The cabled midplane of claim 4, furtherincluding a power layer mounted to the second support plate, the powerlayer arranged to include a plurality of power-carrying conductors forcarrying power between the respective line cards on the first side ofthe cabled midplane, and the respective line cards on the second side ofthe cabled midplane.
 6. The cabled midplane of claim 4, furthercomprising: a third connector set and a fourth connector set mounted tothe second support plate, the third connector set including a pluralityof connectors to connect to respective line cards on the first side ofthe cabled midplane, the fourth connector set including a plurality ofconnectors to connect to respective line cards on the second side of thecabled midplane; and a third support plate parallel to the secondsupport plate to encase the third connector set and the fourth connectorset.
 7. The cabled midplane of claim 6, further including a firstsupport rod between connector slices of the first connector set and thethird connector set and a second support rod between connector slices ofthe second connector set and the fourth connector set, wherein thesecond support plate includes at least one hole for passage of thesupport rod.
 8. The cabled midplane of claim 1, wherein the conductorsof each cable slice of the first plurality of cable slices cross overeach other in such a way that there is at most a single crossoverbetween any two conductors within any individual cable slice of thefirst plurality of cable slices.
 9. The cabled midplane of claim 8,wherein the conductors of each cable slice of the second plurality ofcable slices cross over each other in such a way that there is at most asingle crossover between any two conductors within any individual cableslice of the second plurality of cable slices.